Crystal Sewell knows what she wants to see in the next pope: a combination of the last two.

"I'm a conservative soul," the 29-year-old Reservoir Hill woman said Monday after the midday Mass at St. Alphonsus Church in downtown Baltimore. "I feel like John Paul II had this particular zeal for youth and that brought the youth closer to the Church. Benedict took over with instilling older traditions into today's youth, which brings a whole new focus on what it means to be Catholic today."

Archbishop William E. Lori said the successor to Pope Benedict XVI, to be chosen next month by the College of Cardinals, must be "a faithful and loving teacher" with a "pastor's heart" who is "capable of embracing 1 billion people from every culture and every language on Earth."

The pope surprised Catholics around the world Monday when he told a meeting of cardinals that he lacked the "strength of mind and body" to continue leading the church and would step down at the end of the month after nearly eight years. The former Joseph Ratzinger became the first pope since the 13th century to abdicate voluntarily.

The 85-year-old pontiff is expected to retire to a life of prayer, study and writing.

The faithful hailed the announcement as a reflection of his humility.

"The news, while sad, is yet another example of the pope's selflessness and humility, and presents an opportunity for the Church and the entire world to look with gratitude on his remarkable papacy," said Cardinal Edwin F. O'Brien, the former archbishop of Baltimore.

In a statement from Rome, O'Brien described Pope Benedict as a "staunch defender of human rights and those religiously persecuted" and a "champion for the dignity of all people" who has "offered a much-needed voice for morality and good in a world where both are far too scarce."

O'Brien, elevated to cardinal last year by the pontiff, will participate in the conclave next month to choose his successor. Pope Benedict himself will be too old to vote — the cutoff is age 80. But because all 118 cardinals who can vote were installed by either Pope Benedict or Pope John Paul II, the next pope is expected to lead the church in a similarly conservative direction.

"In terms of substance, we're not going to see a major change," said the Rev. Thomas Reese, a senior fellow at the Woodstock Theological Center at Georgetown University. "We will see a dramatic change in personality and style."

One possible change: The cardinals will weigh whether to elect the first pope from the developing world, where the church is growing most rapidly. Several "papabili" — possible popes — including Cardinals Joao Braz de Aviz and Odilo Pedro Scherer of Brazil, Leonardo Sandri of Argentina, Luis Tagle of the Philippines and Peter Turkson of Ghana are considered candidates.

Former state Sen. Michael Collins said the idea was exciting.

"Will this be the time the Church leaders decide to select a non-European pope?" Collins asked at St. Alphonsus. "I happen to believe, at least in America, our Hispanic brothers and sisters are really the future of our Church, because that's the population that's growing."

The Rev. James Martin, editor-at-large of the Jesuit magazine America, said such a choice would be a "sign that the center of gravity has shifted."

Pope Benedict had spoken of stepping down if he felt incapable of serving. But the announcement Monday still caught Catholics by surprise.

Friends Constantia Jones, 80, of Woodlawn and Evelyn Chittams, 81, of Baltimore's Poppleton neighborhood, said the pope was right to recognize his physical limitations.

While the women said they'd like the next pontiff to be younger and more capable of traveling — Pope Benedict's physician reportedly had advised him not to cross the Atlantic again, as he did for his 2008 visit to Washington, New York and Boston — they were grateful for the pope's service.

Christopher Ruddy, a theologian at the Catholic University of America in Washington, said the pontiff's decision was characteristic of his personality.

"It seemed he knew he was called to this ministry of being pope but had a sense that he is not utterly indispensable," Ruddy said.

Ruddy said the resignation can serve as a reminder that the ultimate leader of the Catholic Church is Jesus Christ.

He said Pope Benedict devoted his papacy to helping believers "encounter the core" of Catholicism through his writing on Christ.

Where Pope John Paul II was "such an extraordinary and dramatic figure" who had "a commanding public presence," Ruddy said, Pope Benedict's contribution will be "quiet and patient and enduring, almost as a seed grows into a plant."

Reese, of the Woodstock Theological Center, said modern medicine has made it more likely that future popes will outlive their ability to fulfill the responsibilities of leading the world's 1.2 billion Catholics.

While Vatican leaders made accommodations for Pope John Paul II, a former sportsman who was slowed in later years by Parkinson's disease and other ailments, canon law does not establish a process for removing an incapacitated pontiff.

Reese said he has "great respect and admiration" for Pope Benedict: "He put the Church first."

The last pontiff to resign was Gregory XII, who was pressured to step down in 1415 to help heal a dispute within the church known as the Great Western Schism. Celestine V, a former monk who cherished solitude, was the last to leave voluntarily, in 1294 after five months in the position.

For centuries, Catholics believed that to resign the papacy was to resist the will of God.

"There is a medieval aura around the job," said Michael Sean Winters, a columnist for the National Catholic Reporter. "The election is inspired by the Holy Spirit, and if you resigned you were betraying the Holy Spirit."

Ratzinger was an academic in his native Germany who served as a theological adviser to the archbishop of Cologne during the Second Vatican Council. He was elevated to archbishop of Munich and Freising in 1977, and named by Pope John Paul II to be prefect of the Congregation for the Doctrine of the Faith in 1981.

It was in that job as the Vatican's chief doctrinal enforcer that he drew international attention as a possible — some said likely — successor to Pope John Paul II.

He was elected pontiff in 2005. Early on, he angered Muslims when he quoted a 14th-century emperor who linked Islam and violence, and alienated Jews when the church reinstated the Latin Mass with its Good Friday prayer for their conversion.

But he later visited synagogues and a mosque, and met with Jewish and Muslim leaders during his trip to the United States. On each of the five days of that 2008 trip, he spoke of the crisis involving children who had been sexually abused by priests, and he met with abuse survivors in Boston, the epicenter of the scandal.

In his first encyclical as pope, he focused on love.

"He is a gentle, almost a courtly man," said Lori, the Baltimore archbishop, "and very, very gracious with a ready smile and a good sense of humor."

Lori called for prayers for the pontiff and for the Church.

"This is a solemn occasion for us, of course, but I hope we would recognize the humanity of this pope who recognized that the stamina required for this role wasn't his any longer," he said. "He readily announced this to the whole world. That takes a marvelously holy and strong person."

As the College of Cardinals meets at the Vatican, members won't be talking about ordaining women, expanding the married priesthood or celebrating same-sex marriage — those matters are settled in the eyes of church fathers.

Reese said the cardinals will ask who among them would be accepted worldwide and is familiar with sensitive matters in certain places, including the sex abuse scandal in America and other countries, and interfaith relations in countries such as India and Lebanon where Catholics and Muslims live side by side.

Martin, the editor at America, said the pope's successor will be a man of holiness and prayer who has the ability to lead a global organization and a zeal for spreading the Gospel

Martin called Pope Benedict's resignation a "noble and selfless act.

"Rare today is the person who would give up such immense power voluntarily," Martin said. "I was very touched by it."